Occupational trichloroethylene hypersensitivity syndrome: Human herpesvirus 6 reactivation and rash phenotypes

Abstract Background Trichloroethylene (TCE) is an industrial solvent which can cause severe generalized dermatitis, i.e., occupational TCE hypersensitivity syndrome. Reactivation of latent human herpesvirus 6 (HHV6) can occur in such patients, which has made TCE known as a causative chemical of drug-induced hypersensitivity syndrome (DIHS). Objective This study aimed to clarify HHV6 status, cytokine profiles and their association with rash phenotypes in patients with TCE hypersensitivity syndrome. Methods HHV6 DNA copy numbers, anti-HHV6 antibody titers, and cytokines were measured in blood prospectively sampled 5–7 times from 28 hospitalized patients with the disease. Results The patients (19 had exfoliative dermatitis (ED) and 9 had non-ED type rash) generally met the diagnostic criteria for DIHS. Viral reactivation defined as increases in either HHV6 DNA (≥100 genomic copies/10 6 peripheral blood mononuclear cells) or antibody titers was identified in 24 (89%) patients. HHV6 DNA, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-5, IL-6 and IL-10 concentrations were remarkably higher in the patients than in the healthy workers ( p p p p Conclusion Reactivated HHV6 and the increased cytokines could be biomarkers of TCE hypersensitivity syndrome. The higher-level reactivation and stronger humoral responses were associated with ED-type rash.